Synergistic combination of alkyl sulfonates, alkylaryl sulfonates and topical antibacterial agents for local antisepsis



United States Patent SYNERGESTIC COMBINATIQN 0F ALKYL SUL- FONATES, ALKYLAR-YL SULFONATES AND TOPHIAL ANTIBACTERIAL AGENTS FOR L0- CAL ANTISEPSIS Gerald M. Compeau, Roselle Park, N.J., assignor to Lehn &"Fink Products Corporation, Bloomfield, N.J., a corporation of Delaware No Drawing. Filed Mar.- 17, 1959, Scr. No. 799,843

Claims. ((1161-58) This invention relates to a bactericidal composition which is especially suitable for application to the human skin, and also, it relates to a method by which pathologic bacteria such as Staphylococcus aureus when present on the skin may be substantially eliminated therefrom.

With the widespreaduse of the antibiotic drugs, a serious danger of staphylococcal infection in hospitals and similar institutions has arisen, because many of the drugs retard-growth rather than kill such pathologic bacteria. The Surgeon General ofthe United States has also called attention tothisfact, thusarousing considerable interest in'seekingaworthwhile-solution;

The Staphylococcus-aureusare transient type bacteria, as against-other-forms-whichnormally reside on the human skin; Conventional antiseptics or body cleansers do not-killStaphylocoecus-aureus, but merely serve as growth retarders or as bacteriostats. Understandably, in hospitals or other areas. in which sterile skin conditions are needed, the conventional compositions are ineffective against such pathologic bacteria, and it is necessary to take extraordinary precautions for assurance against possible infection. Surgery isone activity in hospitals which requires greatest care against possible infection by the pathologic bacteria, but yet the surgical soaps now. being used are far from being satisfactory in accomplishing this goal.

Preparations containing as the sole skin substantive component. an antibacterial agent, such as hexachlorophene, tetramethylthiurarndisulfide, 2,2 thiobis (4 chlorophenol), 2,2 thiobis (4 chloro, 6 methylphenol), etc. reduce the number of bacteria on the skin with prolonged use involving days or weeks ofapplication but. are, ineffective as bactericides against Staphylococcus aureus. Further, neither a surfactant alone nor a low pHis effective in killing the Staphylococcus aureus. However, an anionic surfactant and low pH do exhibit bactericidal activity. It appears that on the acid side of the isoelectric point of proteins, and it maybe considered that bacteria are proteinaceous, theproteinbecomescation active or, stated differently, the larger ion of the ionized protein molecule bears a positivecharge. At the-low pH, the cation of the protein and the anionic surfactant combine to form an insoluble precipitate, resulting in suffocation of the bacteria. Unfortunately, however, the kill of bacteria by means of an anionic surfactant at a low pH was not satisfactory; In this connection, my eventual discovery of the synergism between a skin substantive bacteriostatic compound and the anionic surfactant at a low pH was not foreseeable on the basis of previous knowledge of the individual effects of these materials as regards kill of Staphylococcus aureus.

All anionic surfactants cannot be used for mypurpose. Those anionic surfactants containing an ester group such as dioctyl ester of sodium sulfosuccinate, sulfated secondary alcohols, sulfated monoglycerides, sulfated lauryl alcohol, etc., are unsatisfactorybecause-of a rapid loss of bactericidal activity upon standing or a rapid develop ment of anundesirable odor, rendering it repugnant for use. Ordinary soap cannot exist as such at the pH required for the present invention.

Accordingly, an object of this invention is to provide "icea novel composition having an exceptional property for killing Staphylococcus aureus.

Another object is to provide a composition of' exceptional stability at a low pH and possessing the property of killing Staphylococcus aureus.

Still another object is to provide a method of killing Staphylococcus aureus on the skin by means of a composition of exceptional stability upon standing for prolonged periods of time.

Other objects and advantages will become apparent from the following description and explanation thereof.

It is contemplated in accordance with the present invention to provide a composition'comprising a skin substantive bacteriostatic compound and an anionic surface active hydrocarbon sulphonate, at a pH of about 2 to 4. The composition can be applied to the skin forthe purpose of killing bacteria, including Staphylococcus aureus, without danger of irritation. The composition may be employed as a surgical scrub, a treatment for acne, anunder arm spray deodorant, an after-shave 10- tion or a foot and body powder.

The skin substantive compound of the formulation of the invention is non-toxic and possesses a bacteriostatic effect on bacteria including Staphylococcus aureus. The glass of compounds falling within such a definition are old and well known, thus being understood'by those skilled in the art. For example, hexachlorophene, tetramethylthiuramdisulfide, bithionol, trichlorocarbanilide, 2,2 thiobis (4 chlorophenol), 2,2 thiobis (4 chloro, 6 methylphenol), etc. are skin substantive, non-toxic and do exert a bacteriostatic effect on bacteria, but are not bactericidal when used alone. The quantity in which these compounds are employed varies in accordance with the use, but generally, about 2 to 15% by weight, based on the quantity of anionic surfactant, may be employed; The quantity of bacteriostat may vary outside the above range, in which case less satisfactory results are achieved.

The anionic surfactant to be used with theskin'substantive bacteriostat may be a sulphonated hydrocarbon, such as an alkane sulphonate or an alkaryl sulphonate in which the aryl nucleus is mono or polynuclear, such as benzene, naphthalene, etc. The alkyl substituent on the aryl group may contain from about 1 to 22 carbon atoms. The important consideration is that the com pound be an anionic surfactant. In the alkane sulphonates, the alkyl group contains about 8 to 22 carbon atoms. The sulphonic acid group or groups are attached directly to a carbon atom, providing'a stable carbon to sulfur bond, unlike the anionic surfactants mentioned hereinabove as falling outside of the scope of the invention. There may be one or more sulphonic acid groups in the molecule and the group may be a free acid group or combined with such radicals as ammonium; alkali metal, e.g., sodium, potassium, etc.; substituted ammonia such as the amines; etc. Specific examples of such surfactants are sodium propylnaphthalene sulphonate, sodium dodecyl benzene sulphonate, triethanolamine dodecyl benzene sulphonate, sodium-toluene sulfonate, sodium xylene sulphonate, ammonium butyl naphthalene sulphonate, sodium keryl benzene sulphonate, isopropyl amine tetrapropyl benzene sulphonate, sodium dodecane sulphonate, etc. The anionic surfactant at the desired pH cooperates orsynergizeswith the skin substantive bacteriostat. to effect. av kill. of bacteria. including Staphylococcus. aureusin excess. of what might be predicted on the basis of their individual effects. The synergism exists as long as the two compounds are together in any relative proportions, but the cooperation is particularly effective when the bacteriostat is present in an amount of about 5 to 10% by weight, based on the surfactant.

It is also important that the composition be adjusted to a pH of about 2 to 4 in order to be effective. At a lower pH than the range mentioned, the composition becomes unduly irritating to the skin and thus is preferably avoided; whereas at a higher pH the synergism is adversely influenced to the extent that the composition tends to be ineffective as a bactericide for Staphylococcus aureus. For our purpose, the desired pH of the composition is obtained by the use of an acid buffer which is non-toxic and preferably not odoriferous. Generally, acids having an ionization constant of not more than about 1 10- and as low as about 1x10- and which are non-toxic and lack objectionable odor can be employed for the present invention. Examples of the acids are citric acid, phosphoric acid, acetic acid, lactic acid, propionic acid, tartaric acid, hydroxyacetic acid, etc. Acids such as sulphuric, hydrochloric, nitric, hydrofluoric, chloroacetic, sulfurous, periodic, picric, etc. are either irritating to the skin or impart bad odor, and so cannot be used. For some applications, such as a pre-surgical scrub, the quantity of acid buffer is regulated to maintain a pH of 2-4 when one part of scrub is diluted with five parts of water, otherwise the composition would not be effective against the Staphylococcus aureus bacteria.

To provide a fuller understanding of the present invention, reference will be had to the specific examples.

EXAMPLE I.PRE-SURGICAL SCRUB Parts by weight Triethanolamine dodecylbenzene sulphonate (60% active) 45 Laurie diethanolamide (foam stabilizer) 4 Liquid lanolin (emollient) 1 Hexachlorophene 3 Buffer:

Phosphoric acid 85% (46 parts)] Citric acid monohydrate (19 parts) 2 Triethanolamine (20 parts) Water, q.s. (100 parts) Ethyl alcohol 95% 12 Water, q.s 100 pH, 3.

Using an in vivo test which parallels actual conditions of use, the pre-surgical scrub of Example I without the hexachlorophene reduced the bacterial population on the hands following a 6 minute scrub by 36%. With the addition of hexachlorophene, providing the composition of Example I, the bacterial count was reduced by 92%. In determining the counts, the agar used for plating the samples contained a suitable neutralizer, viz, polyoxyethylene sorbitan monooleate to eliminate bacteriostasis. The percentage reduction values cited above are relative to a scrub under similar conditions using Ivory soap as zero percent reduction.

The effectiveness of hexachlorophene alone, also known as G-11, as a bactericide has been tested by prior Workers. This compound has been evaluated in the form of bar soap, liquid soap or pHisoderm, and found to be a bacteriostat and not to have any more effect than Ivory soap against bacteria. This work is reported in Drug Standards, vol. 19, Nos. 9 and 10, page 170 (1951).

Additional examples are given below.

EXAMPLE II.ACNE PREPARATION Parts by weight Sodium dodecylbenzenesulfonate (50% active)--- 1.4 Sodium xylenesulfonate (40% active) 3.6 Citric acid 0.4

Salicylic acid 0.5 Hexachlorophene 0.1 Ethyl alcohol 95 25.0 Water, q.s 100.0 pH, 3.

This composition is used in the area of the face to combat the organisms associated with acne vulgaris. The

' Sodium xylenesulfonate (40% active) salicyclic acid provides a moderate keratolytic effect, and hexachlorophene is the skin-substantive antibacterial compound. Under standardized conditions of testing (sterile swab sampling) on the faces of test human subjects, the following table shows the synergistic action due to the presence of the hexachlorophene.

Table l Bacteria per square Facial treatment-10 minutes: inch of face Control (water) 34,025 Acne preparationno hexachlorophene 5,500 Acne preparation-0.1% hexachlorophene 52 Suitable neutralizers such as 10% horse serum or polyoxyethylene sorbitan monooleate were used in subculturing the facial swabs to eliminate bacteriostasis. Consulting dermatologists report excellent results are obtained with this preparation in treating their acne patients.

This lotion is used on the face immediately after shaving with no unpleasant smarting or other ill effect. The conditions of use of this preparation do not require the presence of salicylic acid for keratolytic effect, but requires more alcohol for faster evaporation from the skin. The skin-substantive antibacterial compound is bithionol.

EXAMPLE IV.BACTERICIDAL UNDER-ARM SPRAY DEODORANT Parts by weight Sodium dodecylbenzenesulfonate (50% active)--- 1.4 3.6 0.4 0.1

Citric acid 2,2 thiobis (4-chlorophenol) Perfume 0.3 Ethyl alcohol 65.0 Water, q.s 100.0 pH, 3.

The dye solutions have been omitted here, to avoid discoloration of clothing, and the alcohol content has been raised. The skin-substantive antibacterial compound is 2,2 thiobis (4-chlorophenol).

EXAMPLE V.-BACTERICIDAL FOOT AND BODY POWDER Parts by weight Sodium dodecylbenzenesulfonate (95 active powder) 1.1 Citric acid 0.2 3,4,4 trichlorocarbanilide 1.0 Cornstarch 10.0 Perfume 0.7 Talc 87.0

pH (in aqueous extract), 3.

The powders are blended together and are then micropulverized. Here the 3,4,4 trichlorocarbanilide is the skin-substantive antibacterial compound. Due to the low solubility of this compound, it cannot be used in clear liquid preparations but is satisfactory for use in powders, detergent bars and opaque lotions.

E! J EXAMPLE VI.BACTERICIDAL SYNTHETIC DETERGENT BAR Parts by weight Sodium dodecylbenzenesulfonate (95% active powpH (in Water), 3.

These materials are compounded in a suitable mixer and are then extruded in bar form. The tetramethylthiuramdisulfide used here as the skin-substantive antibacterial compound is too insoluble to be used in clear liquid preparations, but is satisfactory for use in powders, detergent bars, and opaque lotions.

Having thus provided a description of my invention along with specific examples, the scope thereof is defined by the appended claims.

I claim:

1. A non-toxic composition comprising a stable anionic surface active sulphonate selected from the group consisting of alkyl sulphonates in which the alkyl group contains approximately 8-22 carbon atoms and alkyl aryl sulphonates in which the alkyl group contains approximately 1-22 carbon atoms and in which the aryl nucleus is selected from the group consisting of benzene and naphthalene, and a non-toxic skin substantive bacteriostatic compound, at a pH of about 2 to 4.

2. A method of killing bacteria on the human skin which comprises applying to the skin the composition of claim 1.

3. The composition of claim 1 wherein the bacteriostatic compound is selected from the group consisting of hexachlorophene, tetramethylthiuramdisulfide, bithionol, trichlorocarbanilide, 2,2 thiobis (4 chlorophenol), and 2,2 thiobis (4 chloro, 6 methylphenol).

4. A method of killing bacteria on the human skin which comprises applying to the skin the composition of claim 3.

5. A non-toxic composition comprising hexachlorophene and a stable alkaryl sulphonate containing an alkyl substituent of about 1 to 22 carbon atoms and an aryl nucleus selected from the group consisting of benzene and naphthalene, at a pH of about 2 to 4.

6. A method of killing bacteria on the human skin which comprises applying to the skin the composition of claim 5.

7. A pre-surgical scrub comprising about 27 parts of triethanolamine dodecylbenzene sulphonate; 4 parts of lauric diethanolamide; 1 part of lanolin; 3 parts of hexachlorophene; about 12 parts of an acid buffer containing 39 parts of phosphoric acid, 19 parts citric acid, 20 parts of triethanola-rnine and 22 parts water; 12 parts ethyl alcohol and 41 parts water.

8. An acne composition comprising about 0.7 parts of sodium dodecylbenzene sulphonate, 1.4 parts sodium xylene sulphonate, 0.4 part citric acid, 0.5 part salicylic acid, 0.1 part hexachlorophene, 23 parts ethyl alcohol and 73.9 parts of water.

9. An after-shave lotion comprising about 0.7 part of sodium dodecyl benzene sulphonate, about 1.4 parts of sodium eXlene sulphonate, about 0.4 part of citric acid, about 0.1 part of bithionol, about 47.5 parts of ethyl alcohol and about 49.9 parts of water.

10. An under-the-arm deodorant comprising about 0.7 part of sodium dodecylbenzene sulphonate, about 1.4 parts of sodium Xylene sulphonate, about 0.4 part of citric acid, about 0.1 part of 2,2 thiobis (4-chlorophenol), about 62 parts of ethyl alcohol and about 35.4 parts of water.

References Cited in the file of this patent UNITED STATES PATENTS 2,634,240 Showalter et al Apr. 7, 1953 2,746,928 Darragh May 22, 1956 2,846,398 Beaver et a1. Aug. 5, 1958 2,898,264 Weber Aug. 4, 1959 2,937,147 Goldwasser May 17, 1960 FOREIGN PATENTS 1,088,387 France Sept. 8, 1954 786,285 Great Britain Nov. 13, 1957 OTHER REFERENCES Wadley: The Evidence Required To Show Synergistic Action of Insecticides and a Short Cut in Analysis, Et-223, June 1945, 7 p. brochure.

Flett et al.: Am. Perfumer and Ess. Oil Review, 48: 12, December 1946, pages 63-4, 69.

Freeman: Surgery, vol. 25, June 1949, pp. 897-901, 167-901.

Harry: Cosmetic Materials, 1st Ed., Leonard Hill Ltd., London (1950), pp. 23-4, 166-8, 272-3 and 312-3.

Shay: Chem. Absts., vol. 45, 1951, p. 7747.

Chemical Abstracts, vol. 47:9562c (1953) (abstract of Masuyama, Japan J. Bacteriol. 5, 263-6 (1950)).

Schwarz et al.: Surface Active Agents and Detergents, vol. H, Interscience PubL, NY. (1958), pp. 231-3 and 320-1.

Sebulex, Reg. Trademark File No. 676,451, March 31, 1959. (First use in commerce April 15, 1958.)

Fein, H. D.: Modern Drug Encyclopedia and Therepeutic Index, 1958, 7th Edition, N.Y., Donnelley Corp, 1958, page 477.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No; 3 l41 821 July 21 1964 Gerald Mo Compeau s in the above numbered pat- It is hereby certified that error appear tters Patent should read as en'b requiring correction and that the said Le corrected below Column 6,, line 11 for "exlene" read xylene line 41.1 strike out; "'167-90l" Signed and sealed this 17th day of November 1964.,

(SEAL) Attest:

EDWARD J. BRENNER ERNEST W. SWIDER' Attesting Officer Commissioner of Patents 

1. A NON-TOXIC COMPOSITION COMPRISING A STABLE ANIONIC SURFACE ACTIVE SULPHONATE SELECTED FROM THE GROUP CONSISTING OF ALKYL SULPHONATES IN WHICH THE ALKYL GROUP CONTAINS APPROXIMATELY 8-22 CARBON ATOMS AND ALKYL ARYL SULPHONATES IN WHICH THE ALKYL GROUP CONTAINS APPROXIMATELY 1-22 CARBON ATOMS AND IN WHICH THE ARYL NUCLEUS IS SELECTED FROM THE GROUP CONSISTING OF BENZENE AND NAPHTHALENE, AND A NON-TOXIC SKIN SUBSTANTIVE BACTERIOSTATIC COMPOUND, AT A PH OF ABOUT 2 TO
 4. 3. THE COMPOSITION OF CLAIM 1 WHEREIN THE BACTERIOSTATIC COMPOUND IS SELECTED FROM THE GROUP CONSISTING OF HEXACHLOROPHENE, TETRAMETHYLTHIURAMDISULFIDE, BITHIONOL, TRICHLOROCARBANILIDE, 2,2'' THIOBIS (4 CHLOROPHENOL), AND 2,2'' THIOBIS (4 CHLORO,6 METHYLPHENOL). 